RADIOTHERAPY FOR CERVICAL-CANCER WITH HIGH-DOSE-RATE BRACHYTHERAPY - CORRELATION BETWEEN TUMOR SIZE, DOSE AND FAILURE

This is a retrospective analysis of 659 patients with cervical squamous cell carcinoma with a minimum follow-up of 2 years at Keio University Hospital between May 1974 and March 1990. All patients were treated with external radiation (50 Gy) and high-dose rate (HDR) intracavitary brachytherapy (20-34 Gy). The 5-year survival rates in each stage gradually decreased with the advance of the stage (I, 84%; II, 71%; II1, 47%; and IVa, 12%). When 366 patients with stage III were classified into three groups according to tumor size, i.e. small (S, 102 patients), medium (M, 145) and large (L, 119), a survival gradient of small > medium > large was demonstrated and the differences between them were significant. At follow-up visits conducted between 1 and 2 months after completion of treatment, 135 patients (20%) had physical indications of residual disease. The larger the tumor size, the more likely was residual disease by 2 months. The patients with residual disease had a significantly higher rate of the pelvic failure than those without it. There was no significant correlation between radiation doses by RALS and pelvic failure rates, except in the stage III-L group. In the stage III-L group, intracavitary doses of 24 Gy or less to point A could be correlated with the higher pelvic failure rate and the lower survival rate, in contrast to doses of 27 Gy or more. The incidence of major rectosigmoid complications was 11.8% with doses of 24 Gy or less to point A, 8.1% with 27 Gy and 19.2% with doses of 30 Gy or more. The incidence of major rectosigmoid complications is likely to increase with doses higher than 30 Gy. The incidence of severe urinary complications was less than 1.5% with doses between 20 and 34 Gy. It was concluded that 27 Gy by HDR brachytherapy may be recommended for cervical cancer except for larger tumors or tumor that did not regress promptly. Such poor-prognosis patients should be targeted for the early adjuvant or salvage therapy.